# Class virtual Cf_machine.next

    class virtual [['i, 'o]] next : object .. end

Use `inherit ['i, 'o] next` to derive a class that implements an intermediate state in a machine.

    method private virtual guard : (('i, 'o) #next, 'i, 'o, unit) Cf_state_gadget.guard

The guard evaluated by this state of the machine.

    method next : 'a. (('i, 'o) #next as 'b, 'i, 'o, 'a) Cf_state_gadget.t

Use `obj#next` to transition the state of the machine by storing `obj` in the state of the gadget and applying `Cf_state_gadget.guard` `self#guard`.